Robust detections of H \(\alpha \)  emission from planetary-mass objects exist only for the PDS 70  companions [1]}, [2]} and for Delorme 1 (AB)b [3]}.
The latter, a circumbinary low-mass companion, exhibits hydrogen- and helium-line emission, which is naturally explained by an accretion scenarioThere are several arguments against the alternative origin, chromospheric activity; see [3]}..
The inferred accretion rate onto Delorme 1 (AB)b is \(\dot{M} \approx 10^{-9.5}\)  or \(\approx 10^{-8}~M_{\mathrm {J}}\,\mathrm {yr}^{-1}\) , depending on the model used to convert the line luminosities into \(\dot{M} \) . Even at \(\dot{M} \approx 10^{-8}~M_{\mathrm {J}}\,\mathrm {yr}^{-1}\) ,
extinction by either the gas or the dust (Figures REF  or REF , respectively) is entirely negligible.
<FIGURE>